Impaired immune function

Chemical-mediated immune suppression has been identified from the experimental study of several wildlife species. Harbour seals fed either chemically contaminated fish from the Wadden Sea or imcontaminated fish were found to have differing immune responses, with the exposed group showing lowered immune response to microbial infections and certain types of cancer. "" Mink fed fish taken from below a discharge point for bleached Kraft pulp mill effluent have also shown impaired immune function, " showing that the non-accnmillative chemicals in this effluent can actively disrupt endocrine associated functions. 

Humans given zinc supplements should be aware of possible complications (Fosmire 1990). Low intakes of 100 to 300 mg of zinc daily in excess of the recommended dietary allowance of 15 mg Zn daily may produce induced copper deficiency, impaired immune function, and disrupted blood lipid profiles. Patients treated with zinc supplements (150 mg daily) to control sickle cell anemia and nonresponsive celiac disease developed a severe copper deficiency in 13 to 23 months normal copper status was restored by cessation of zinc supplements and increased dietary copper (Fosmire 1990). 

Developmental Changes that Impair Immune Function.54... 

DEVELOPMENTAL CHANGES THAT IMPAIR IMMUNE FUNCTION... 

Food-borne pathogens are not so readily treatable, and disease outbreaks (a term used to describe food poisoning events that have a single source and that affect many persons at one time) are not uncommon. Individual cases also occur, but these are not so easily countable. In any case, the total annual burden of disease from food-borne pathogens in the United States is said by the CDC to be in the tens of millions. Most of these cases amount to nothing but the extreme discomfort associated with vomiting and diarrhea, but mortality can be high in certain subpopulations - children, the elderly, those with impaired immune functions. 

The activity of vitamin A is related to vision process, tissue differentiation, growth, reproduction, and the immune system. A deficiency of this micronutrient mainly leads to visual problems, impaired immune function, and growth retardation in children. Hypervitaminosis could lead to hepatotoxicity, affect bone metabolism, disrupt lipid metabolism, and teratogenicity [417]. The isomerization of P-carotene, due to technological processes in foods, leads to a reduction of the vitamin A activity it is therefore important to analyze it. 

The answer is D. Impaired immune function in severe combined immunodeficiency (SCID) is the direct result of blocked DNA synthesis due to inadequate supplies of de-oxyribonucleotides in B and T cells. This effect arises by dATP-induced allosteric inhibition of ribonucleotide reductase, which catalyzes reduction of the 2 -hydroxyl groups on ADP and GDP to form dADP and dCDP. The ultimate cause of many cases of SCID is adenosine deaminase deficiency, which leads to accumulation of dATP and consequent inhibition of ribonucleotide reductase. Although the other enzymes mentioned are also involved in purine nucleotide metabolism, their deficiencies do not lead to SCID. 

Like folate and vitamin C, vitamin B6 (pyroxidine) is water soluble and like folate has several vitamers. Vitamin B6 may be involved in more bodily functions than any other nutrient (Tambasco-Studart et al., 2005), is a cofactor for many enzymes, especially those involved in protein metabolism, and is also a cofactor for folate metabolism. Vitamin B6 has anticancer activity (Theodoratou et al., 2008), is a strong antioxidant (Denslow et al., 2005), is involved in hemoglobin biosynthesis, lipid and glucose metabolism and immune and nervous system function. Possible consequences of deficiency include anemia, impaired immune function, depression, confusion, and dermatitis (Spinneker et al., 2007). Vitamin B6 deficiency is generally not a problem in the developed world, but there could be as yet poorly defined consequences of suboptimal intake particularly for the elderly. 

Antiviral agents (qv) (15—17) are used in attempts to combat the devastating effect of HIV on the immune system. As of this writing there are three principal approaches to the treatment of AIDS (/) use of anti-HIV agents to destroy the virus or control its growth the National Cancer Institute (NCI) encourages submission of synthetic and characterized natural products for anti-HIV screening (18) (2) immunotherapy to restore impaired immune functions and (3) treatment of specific opportunistic infections or tumors. 

White Phosphorus. Limited information on the immunotoxicity of inhaled white phosphorus was located. As discussed in Section 2.2.1.2, decreased leukocyte levels were observed in workers exposed to an unknown concentration of white phosphorus via inhalation, oral, and dermal routes (Ward 1928). It is not known if the decrease in leukocyte levels would result in impaired immune function. 

The human data suggest that the immune system is a target of white phosphorus toxicity however, no information on the potential of white phosphorus to impair immune function is available. Animal studies assessing the results of a battery of immune function tests could be useful in determining the immunotoxic potential of white phosphorus. Information on different routes of exposure could be useful in assessing if effects are route specific. 

Brandacher G, Winkler C, Schroecksnadel K, Margreiter R, Fuchs D. Antitumoral activity of interferon-gamma involved in impaired immune function in cancer patients. Curr Drug Metab 2006 7 599-612. 

Zinc and Immunity. Zinc is required for Immunocompetence. Recently published reviews have detailed the role of zinc (92-95). Early clinical descriptions of zinc deficiency and impaired Immune function were first reported by Brummerstedt et al.(96) who reported that calves with a genetically acquired inability to absorb zinc suffered from stunted growth, several skin disorders, viral and fungal infections, and atrophied thymus glands. These symptoms could be reversed by the administration of large amounts of dietary zinc. 

Protein energy malnutrition occurs with high frequency (30%-50%) in hospitalized patients as well as in populations in chronic care facilities as either an acute or a chronic problem. These individuals suffer from inadequate nutrition due to a disease or depression, and are susceptible to infections due to impaired immune function. Surgical patients with protein energy malnutrition exhibit delayed wound healing with increased length of... 

Kwashiorkor develops when there is adequate calorie but a relatively inadequate protein intake. These patients generally are well nourished but are extremely catabolic, usually secondary to trauma, infection, or burns. There is depletion of visceral (and to some degree somatic) protein pools with relative adipose tissue preservation, and hypoalbuminemia and edema are commonly seen. In the setting of severe metabolic stress and protein deprivation, kwashiorkor may develop rapidly and may result in impaired immune function. 

To further impair immune function, the defects described above have also been combined through selective crossbreeding, resulting in beige-nude and SCID-beige mice. These mice lack T and NK cells and T, B and NK cells, respectively. Examples of how these mice have been used are shown in Tables 10.1-6 and 10.1-7. In addition to broad cellular defects described above, a number of other immunodeficient mice created by genetic engineering have been studied. 

Preclinical studies have shown that impaired immune function determined using a variety of assays, e.g., the plaque-forming cell (PFC) assay, lymphocyte proliferation, delayed-type hypersensitivity, and NK cell activity, is associated with decreased resistance toward experimental infections (Luster et al., 1994). When a drug candidate has been shown to impair immune function in animal studies, the question arises whether similarly negative effects can also be seen in treated human subjects. 

Chlordane, DDT, hexachlorobenzene, and Immunosuppression (impair immune functions)... 

Bliznakov, E.G., Restoration of Impaired Immune Functions in Aged Mice by Coenzyme Q, paper presented at 4th hit Congr. Immunol. Workshop, The Immunobiology of Aging, Paris,... 

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